Electrochemical Behavior of Sodium Tungsten Bronze Electrodes in Acidic Media

Abstract

The electrochemical behavior of sodium tungsten bronze electrodes has been examined in helium-saturated 1N H//2SO//4. Several techniques have been employed, e. g. , steady-state polarization, potentiodynamic scanning, galvanostatic charging, and open-circuit decay of electrode potential. New data involving potential-pH, rotating-disk, and thermogravimetric measurements on the sodium tungsten bronze electrode are also reported. The results indicate that the surface layer of a strongly anodized bronze electrode is depleted of sodium and its composition may approach WO//3. The reduction of a preoxidized (and hence sodium-depleted) sodium tungsten bronze electrode produces hydrogen tungsten bronze.